Confounding and the healthy worker survivor effect (HWSE) represent major methodological challenges in epidemiology, particularly in studies of low-dose exposures, where effect sizes are small and risk estimates can be readily distorted by bias. This systematic review aimed to summarize the methods used to adjust for confounding and the HWSE in studies of medical radiation workers. We systematically searched PubMed and Embase for studies of medical radiation workers from inception through June 30, 2025. Studies reporting excess risk estimates for any health outcomes associated with occupational radiation exposure were included. Study selection followed the PECO (Population, Exposure, Comparator, Outcome) criteria, and data were synthesized descriptively. The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and was registered in PROSPERO (CRD42024589851). Sixteen eligible studies from 3 countries were identified, all of which were rated as high quality. To control for confounding, regression was used in all studies, followed by stratification (62.5%) and restriction (18.8%). Age, sex, and birth year were adjusted for in all models, with smoking being the next most frequently controlled variable. To mitigate the HWSE, only a single approach, adjustment for employment characteristics, was identified, and it was applied in 3 studies (18.8%). No other approaches, including restriction or g-methods, were employed. Although confounding is generally addressed using conventional analytical approaches, the HWSE has rarely been considered in studies of medical radiation workers. More comprehensive strategies that explicitly account for the HWSE are needed to improve the validity of risk estimates, particularly in low-dose occupational studies.

Purpose: This study was aimed to identify the effect of Mulligan knee taping (MKT) application on the hip joint muscle activity and lower extremity kinematic during single leg squat. Methods: Twenty healthy male partisipants, aged between 19 and 29 years, were measured for hip joint muscle activity, medial knee displacement, and hip adduction angles according to the application of MKT. In single leg squat, the eccentric, isometric, and concentric contraction phases were performed until the knee flexed at a depth of 60°. The muscle activity (unit, %MVIC) of hip joints in each phase and the medial knee displacement (unit, cm) and hip adduction angle (unit, °) were analyzed before and after the application of MKT during single leg squat. All measurements were performed with the dominant leg, and the order of MKT and non-taping was randomly determined by drawing lots. Results: During single leg squat, the muscle activity of the gluteus maximus muscle in the eccentric and isometric contraction phases significantly increased when MKT was applied than when non-taping (p=0.048 and p=0.012, respectively). There was no statistically significant difference between the muscle activity of other lower extremity muscles and the medial knee displacement and hip adduction angle (p＞ 0.05). Conclusion It was confirmed that the activity of the gluteus maximus muscle increased in the case where single leg squat was performed after applying MKT, compared to the case where it was performed without application. Therefore, MKT application is recommended to increase the muscle activity of the gluteus maximus during single leg squat.